We consider degenerate Kolmogorov-Fokker-Planck operatorsLu=∑i,j=1qaij(x,t)∂xixj2u+∑k,j=1Nbjkxk∂xju−∂tu,(x,t)∈RN+1,N≥q≥1 such that the corresponding model operator having constant aij is hypoelliptic, translation invariant w.r.t. a Lie group operation in RN+1 and 2-homogeneous w.r.t. a family of nonisotropic dilations. The coefficients aij are bounded and Hölder continuous in space (w.r.t. some distance induced by L in RN) and only bounded measurable in time; the matrix {aij}i,j=1q is symmetric and uniformly positive on Rq. We prove “partial Schauder a priori estimates” of the kind∑i,j=1q‖∂xixj2u‖Cxα(ST)+‖Yu‖Cxα(ST)≤c{‖Lu‖Cxα(ST)+‖u‖C0(ST)} for suitable functions u, where Yu=∑k,j=1Nbjkxk∂xju−∂tu and‖f‖Cxα(ST)=supt≤Tsupx1,x2∈RN,x1≠x2|f(x1,t)−f(x2,t)|‖x1−x2‖α+‖f‖L∞(ST). We also prove that the derivatives ∂xixj2u are locally Hölder continuous in space and time while ∂xiu and u are globally Hölder continuous in space and time.